THURSDAY, July 3, 2014 (HealthDay News) -- Teen drinkers who also use drugs run a greater risk for serious health problems and death, a new U.S. government study shows.

Researchers analyzed data on underage drinkers (aged 12 to 20) treated at U.S. hospital emergency rooms in 2011, and found that 20 percent of all hospital emergency department visits involving underage drinkers result in serious health outcomes.

Yet, while 12 percent of those visits involving drinking alone led to serious outcomes, the rate of serious outcomes among underage drinkers who also used drugs jumped to 33 percent, the U.S. Substance Abuse and Mental Health Services Administration (SAMHSA) researchers found.

Those serious outcomes included hospitalization, transfer to another health center after their emergency department visit, or death.

"The 9.3 million underage drinkers across America are putting their health and futures at risk -- even more so when they combine alcohol with drugs," SAMHSA Administrator Pamela Hyde said in a government news release.

"The start of summer is a good opportunity for parents and other concerned adults to talk with teens and young adults about the dangers of underage drinking and drug use," she added.

SAMHSA has an underage drinking prevention program called "Talk, They Hear You." It's meant to help parents and other caregivers talk to children about the risks of underage drinking.